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Sunni Robertson on how a kingfisher inspired a bullet train

Biomimicry is using nature to find sustainable solutions to human problems. Japanese engineers used a bird called a kingfisher to help redesign a bullet train.

In a world where scientists are using nature’s best ideas and imitating natural designs and processes to solve human problems, a kingfisher can inspire a bullet train. That’s exactly what happened in Japan in the late 1990s.

This new discipline – using nature to find sustainable solutions to human problems – is called biomimicry.

Japanese companies have operated bullet trains since 1964. They typically travel up to 300 km/h (186 mph). Image Credit: D A J Fossett

EarthSky spoke to Sunni Robertson of the San Diego Zoo, a center for biomimicry research and education. She told us how in the late 90’s Japanese engineers modeled a bullet train after a kingfisher, which is a bird found in many parts of the world. Kingfishers have a large head and a long, narrow beak.

In Japan, they have these very fast bullet trains. They were getting so fast that the typical bullet shape was causing a loud booming sound when these trains would exit typical train tunnels.

The booming, it turned out, had to do with the shape of the face of the train.

And the reason this booming was happening, they discovered, is that this cushion of air was building up in front of that speeding train, going like 300 kilometers an hour. The sound was waking up people who lived nearby. It disturbed the wildlife.

But one of the engineers on the team trying to solve the problem was a birdwatcher.

He had witnessed a kingfisher bird diving down through the air, going into the water and creating very little splash. So he thought, I wonder if I could apply this principle to the shape of the front of the bullet train. And so they did model the front of the train like the kingfisher’s face. It has a pointy part to it just like the beak of the kingfisher. And sure enough when they tried out that new model, it moved through without creating the boom. And it saved them 10-15% more energy because it was more aerodynamic.

Robertson said kingfishers aren’t the only birds that have inspired engineers and designers. She said that peacocks, too, hold some of nature’s secrets.

The San Diego Zoo is partnered with Qualcomm, and we are helping them with their new Mirasol technology. Essentially, they’ve created a new type of display screen, and it’s inspired by peacock feathers, butterfly wings, and other animals that produce structural color. When you look at peacock feathers, and you see all those green, blue, purple colors, you’re not seeing pigment, you’re actually seeing structures in the feathers that allow them to reflect back certain colors.

She explained that Qualcomm’s new display screens have a special internal structure that allows them to reflect ambient light to produce certain colors. Because the colors come from reflection, not production by the screen itself, these screens use less energy.

Robertson said that many different animals have inspired all kinds of innovation, which is one reason the San Diego Zoo is a center for biomimicry research and innovation. She talked about snakes, for example, which have heat receptors similar to human pain receptors, and so might help medical researchers better understand how to treat chronic pain in humans. Another example: alligators have incredible immune systems. Researchers in Louisiana are figuring out how we might use their cells to help treat diseases found in humans.

Ideas from nature help solve human problems. Japanese researchers successfully reduced noise by modeling the front of a bullet train after a kingfisher’s head. Qualcomm’s Mirasol display uses microscopic reflective units similar to those in the colorful wings of butterflies. Biological features from animals may give new ways to treat disease. In many ways, biomimicry enables science to imitate natural designs to develop better technologies for human use.